Metallic-denture-drawing die



R. M. CRAIG.

METALLIC DENTURE DRAWING DIE.

APPLICATION FILED JUNE 19, 1919:

1,392,919, Patented Oct. -11, 1921.

HGEIJ INVENTOI? l foes/er Mme: Gm/s, 43?

NE Y

UNITED STATES PATENT OFFICE.

ROBERT M. CRAIG, OF-WILKINSBUR-G, PENNSYLVANIA.

METALLIC-DENTURE-DRAWING DIE.

Application filed June 19,

To all 7.0 72.0171. it may concern:

Be it known that I, Ixonnnr Manon CRAIG, a citizen of the United States, residing at \Vilkinsburg, in the county of Allegheny and State of Pennsylvania, have invented a certain new and useful Improvement in Metallic Denture Drawing Dies, whereof the following is a specification, reference being had to the accompanying drawing.

It is the ob yect of my invention to provide a die of special construction for drawing a primarily plane strip of sheet metal of uniform thickness to form an I-bar having opposite concave faces of substantially cylindriform curvature, so that the opposite longitudinal edges of said bar are thicker than the middle portion thereof throughout its length. Such an I-bar is punched to form blanks for making denture backings to hold porcelain tooth facings, in accordance with the process of making metallic denture backings whichis claimed in my copending application Serial No. 305,421 filed June 19. 1919, for Letters Patent of the United States 1,353,565 granted September 21st, 1920.

My invention includes the various novel features of construction and arrangement herein specified and claimed.

In said drawing; Figure I is a perspective view of a strip of sheet 'metal of uniform thickness.

Fig. II is a perspective view of an. I-bar drawn from said strip shown in Fig. I.

Fig. III is a perspective view of a pair ofdies, with said strip engaged therein.

Fig. IV is a central vertical sectional view of said dies and strip shown in Fig. III.

Fig. V is a front face view of said dies.

Fig. VI is a plan view of the lower die member shown in Figs. IV and V.

Referring to Fig. I; it is to be understood that the strip of sheet metal 1 is of uniform thickness and uniform width throughout its length. 7

Referring to Fig. II; the I-bar 2, formed from said strip 1, has its opposite faces 3 concavely and substantially cylindriformly curved throughout its length so as to form a thin web 1 with opposite thick longitudinal edges 6 of the same transverse cross section, throughout its length.

Referring to Figs. IV, V and VI; the lower die block 7 has vertical recesses 8 in its ends for engagement with suitable parallel guiding supports in an ordinary die Specification of Letters Patent.

Patented Oct. 11, 1921'. 1919. Serial No. 305,422.

press. Said die member 7 has the trough shaped passage 10 extending transversely across 1t, intermediate of its lengtlnand of the desired width of said I-bar 2. Said passage 10 hasthe convex ridge 11, intermediate of its length and of the desired cylindriform configuration of the lower face of said I-bar 2; but said passage slopes both ways, in the direction of its length, so as to be deeper at both its front and rear than at said ridge and thus afford suitable clearance to receive said strip 1 at the front face of said die member, and permit the free passage of said I-bar 2 at the rear face of said die member.

The upper die block 151 has vertical recesses 15 at its opposite ends, registering with the recesses 8, for engagement with, said supports of the die press, and has the downwardly extending convex projection 17 registering with said passage 10. Said projection, at its shoulder 18, is of the desired cylindriform configuration of the upper surface of said I-bar 2, but slopes therefrom toward its front face, as indicated at 19, to facilitate the traverse of said strip 1. Said projection 17 is cut away, as indicatedat 20, in its extent rearwardly from said shoulder 18, to afford clearance for the withdrawal of said I-bar 2. j I

In operating said drawing die members 7 and 14, to draw the I-bar 2 aforesaid; they are first separated to a suflicient vertical extent to permit the strip 1 to extend loosely between them to such length as to permit its forward end 22 to be engaged by a suitable gripping device, by which it may thereafterbe drawn through said passage 10. Thereupon, said upper die block 14 is pressed downwardly, conveniently by screws 21 in spaced relation intermediate of its length, until the two members 7 and 1 1 are in the position shown in Fig. V. Thereupon, said strip is drawn through said passageway, in the direction of the arrow shown in Fig. III, and thus reduced to form the desired I -bar 2.

Referring to Fig. V;"it may be observed that the opposite edges of said passage 10 are not parallel, but so inclined, vertically, that the upper surface of said I-bar is slightly wider than the lower surface. That peculiar configuration of said passage, and consequent formation of said I-bar, is designed to permitslight deformation of the thick edges 6 of said bar by the operation of punching blanks therefrom, by means of the improvement In processes of making metallic denture backings, which 1s claimed I, in saidLetters Patentof the United States my claims to such construction and arrange' ment'of drawing dies as to produce a bar the opposite longitudinal edges of which are not parallel. Therefore, I do not desire to limit myself to the precise details ofconstruction and arrangement herein set forth, as itis obvious that various modifications may be made therein without departing from the essential features ofvmy invention, as cle- V fined in the appended claims.

It is to be noted that the ordinary mechanism for forming I-bars includes several pairs of respectively differently shaped die rollers, between which the metal is successively passed while said rollers arepositively rotated, to effect successive steps in the reduction of the metal to; the desired form,

and that my improved mechanism is ad vantageous not only in that it is less costly to construct, but may be used to effect the desired result by a single operation, However, it is to' be understoodthat a metal strip 1 may be reduced tothe form 2 by a series of drawing operations with my .im-

proved mechanism; theopposed die'members 7 and 14 being progressively adjusted,

toward-each other, accordingly. I claim:

1. In mechanism for forming an I-bar 1 from a primarily plane strip of sheet metal the combination with a die member having a trough shaped passage'with a ridge, extending transversely to the length of said pass sage, of convex configuration corresponding 1 withthe desired cylind iform configuration of one face of the-bar to be drawn; said passage being inclined in both directions from said ridge so as to afford clearance for the introduction of said stripat the front of said passage and clearancefor the withdrawal of said bar at'the rear .of said pas-,

sage; the opposite longitudinal edges of said 7 passage being parallel with each other in the direction of its length and inclined to each othertranseversely to its length; of

another die memberhaving a projection registering with said passage. and having a shoulder. extending transversely to the length of said passage, of convex configuratlOIl corresponding Wlllll the desired cylindriform configuration of the proximal face of the bar to be drawn; said projection being inclined from said shoulder toward the front of said die member, to afford clearance for the introduction of said strip, and said projection'being cut away from said shoulder to the rear face of said die member to afford clearance for said I-bar; said die members havingsimilar and registered recesses at their opposite ends for engagement with parallel guiding supports; whereby said members are adjustable in variable spaced relation with each other, to vary the dimensions of said passage between said ridge and shoulder, and thus vary the deforming effect of said die members upon said strip.

2.In mechanism for forming an I-bar from a primarily plane strip of sheet metal; the combination with a die member having a trough shaped passage with aridge extending transversely to the length of said passage, of convex configuration corresponding with the desired cylindriform' configtr.

ration of one face of the bar to be drawn; said passage being inclined 1n both directions from said ridge so as to afford clearance for the introduction of said striprat the front of said passage andiclearance for the withdrawal ofsaid bar at the rear of said passage; the opposite: longitudinal edges of said passage beingparallel with .die member to afford clearance for said I- bar; said die members having similar and registered recesses atrtheir opposite ends,

for engagement with guiding and supportmg means; whereby said members aread- .justable in variable spaced relation with each other, to' vary the dimensions of said passage betweenvsaid ridge and shoulder, and thus vary the deforming effect of'said die members upon said'strip.

3fIn, mechanism for: forming an I-bar froma primarily plane strip of sheet metal; the combiuationwi-th a die member having a trough shaped passage with a ridge extending transversely to the length of said passage, of convex configuration correspondingwith the. desiredconfigurationof one face'of the bar to bedrawn said passage'heing inclined inboth directions from said ridge so as to'aiford clearance for the introduction of said strip at the front of said passage and clearance for the withdrawal of said bar at the rear of said passage; of another die member having a projection registering with said passage, and having a shoulder, extending transversely to the length of said passage, of convex configuration corresponding with the desired configuration of the proximal surface of the bar to be drawn; said projection being inclined from said shoulder toward the front of said die member, to afford clearance for the introduction of said strip, and said projection being cut away from said shoulder to the rear face of said die member to afford clearance for said I-bar; said die members having similar and registered recesses at their opposite ends for engagement with guiding and supporting means; whereby said members are adjustable in variable spaced relation with each other, to vary the dimensions of said passage between said ridge and shoulder, and thus vary the deforming effect of said die members upon said strip.

i. In mechanism for forming an I-bar from a primarily plane strip of sheet metal; the combination with a die member having a trough shaped passage with a ridge extending transversely to the length of said passage; said passage being inclined so as to be deeper at each end. than at said ridge; the opposite longitudinal edges of said passage being parallel with each other in the direction of its length and inclined to each other transversely to its length; of another die member having a projection registering with said passage, and having a shoulder; said projection being inclined from said shoulder toward the front of said die member; said die members having registered recesses for engagement with guiding means; whereby said members are adjustable in variable spaced relation with each other, to vary the dimensions of said passage between said ridge and shoulder, and thus vary the deforming effect of said die members upon said strip.

5. In mechanism for forming an I-bar from a primarily plane strip of sheet metal; the combination with, a die member having a trough shaped passage with a ridge extending transversely to the length of said passage; said passage being inclined so as to be deeper at each end than at said ridge; the opposit longitudinal edges of said passage being parallel with each other in the direction of its length; of another die member having a projection registering with said passage, and having a shoulder; said projection being inclined from said shoulder toward the front of said die member; said die lllGlllllGiS having registered recesses for engagement with guiding means; whereby said members are adjustable in variable spaced relation with each other, to vary the dimensions of said passage between said ridge and shoulder, and thus vary the deforming effect of said die members upon said strip.

6. In mechanism for forming an I-bar from a primarily plane strip of sheet metal the combination with a die member having a trough shaped passage with a ridge extending transversely to the length of said passage; said passage being inclined so as to be deeper at each end than at said ridge; of another die member having a projection regist-ering with said passage, and having a shoulder; said projection being inclined from said shoulder toward the front of said die member; said die members having registered recesses for engagement with guiding means; whereby said members are adjustable in variable spaced relation with each other, to vary the dimensions of said passage between said ridge and shoulder, and thus vary the deforming effect of said die members upon said strip.

7. In mechanism for forming an I-bar from a strip of metal; the combination with a die member having a trough shaped passage with a ridge extending transversely to the length of said passage of convex configuration corresponding with the desired cylindriform configuration of the proximal face of the bar to be drawn; the opposite longitudinal edges of said passage being parallel with each other in the direction of its length and inclined to each other transversely to its length; of another die member having a projection registering with said passage. and of convex configuration corresponding with the desired cylindriform configuration of the proximal face of the bar to be drawn; said members being adjustable in variable spaced relation with each other, to vary the dimensions of said passage between said ridge and shoulder, and thus vary the deforming effect of said die members upon said strip.

-8. in mechanism for forming an I-bar from a strip of metal; the combination with a die member having a trough shaped passage with a ridge extending transversely to the length of said passage of convex configuration corresponding with the desired cylindriform configuration of the proximal face of the bar to be drawn; the opposite longitudinal edges of said passage being parallel with each other in the direction of its length; of another die member having a projection registering with said passages, and of convex configuration corresponding with the desired cylindriform configuration of the proximal face of the bar to be drawn; said members being adjustable in variable spaced relation with each other, to vary the dimensions of said passage between said ridge and shoulder, and thus vary the deforming effect of said die members upon said strip.

9. In mechanism for forming an I-bar from a strip of metal; the combination with a die member having a trough shaped passage with a ridge extending transversely to the length of said'passage of convex con figuration corresponding with the desired concave cylindriform configuration of theproximal face of the bar to be drawn; of another die member having a projection registering wi h said passage, and of convex configuration corresponding with the desired conave cylindriiorm configuration of the proximal face of the bar to be drawn; said. members being adjustable in variable spaced relation with. each other, to vary the dimensions of said passage between said ridge and shoulder, and thus vary the deforming efi ectof said die members upon said strip. v

10. Mechanism constructed and arranged to form an I -bar from a primarily plane StllPOf meta including a die member having a trough shaped passage with a ridge extending transversely to the length of said passagecorresponding with the desiredconcave configuration of the proximal face of the bar to be drawn; of another die member having a projection registering with said passage, and corresponding with the desired concave configuration of the proximal face or" the bar to be drawn; whereby said strip may be reduced to form said I- bar by drawing it through said passage.

In testimony whereof, I have hereunto signed my name at Wilkinsburg, Pennsylvania, this sixth day of November, 1918.

' ROBERT M. CRAIG- Vitnesses 'R. A. COLEMAN,

H. R. CRAIG. V 

